Comments on research and other knowledge developments in occupational and public health and current events in politics related to public health, occupational health, and the environment.

Thursday, March 03, 2005

Alcohol Consumption Protects Against Mortality in the Elderly

Years ago, Peto and Doll attributed 34% of cancer to diet, a canonical number widely quoted today by many authorities actively disinterested in industrial chemicals and pollution as causes of cancer. Doubtless among those dietary causes was alcohol.

Here, Peto and Doll report a 23-year prospective study of 12 000 male British doctors aged 48–78 years in 1978, involving 7000 deaths. …In this elderly population, with mean alcohol consumption per drinker of 2 to 3 units per day, the causes of death that are already known to be augmentable by alcohol accounted for only 5% of the deaths (1% liver disease, 2% cancer of the mouth, pharynx, larynx, or oesophagus, and 2% external causes of death) and were significantly elevated only among men consuming >2 units/day. Vascular disease and respiratory disease accounted for more than half of all the deaths and were both significantly less common among current than among non-drinkers; hence, overall mortality was also significantly lower (relative risk, RR 0.81) …Adding ex-drinkers to current drinkers …still showed that ischaemic heart disease (0.72), respiratory disease (0.69) and all-cause (0.88) mortality were significantly lower than in the non-drinkers.

BrooklynDodger notes that this is a study of the later period of life when the population feels the full force of mortality. That said, even at this age each death avoided is worth 10 years or more to the individual who didn’t die. These reduced relative risks indicate many more lives prolonged than similar reductions among 30 year olds. BrooklynDodger hasn’t reviewed the full text to determine what types of respiratory mortality were reduced among the drinkers.

Background To relate alcohol consumption patterns to mortality in an elderly population.Methods We undertook a 23-year prospective study of 12 000 male British doctors aged 48–78 years in 1978, involving 7000 deaths. Questionnaires about drinking and smoking were completed in 1978 and once again in 1989–91. Mortality analyses are standardized for age, follow-up duration, and smoking, and (during the last decade of the study, 1991–2001) subdivide non-drinkers into never-drinkers and ex-drinkers.Results In this elderly population, with mean alcohol consumption per drinker of 2 to 3 units per day, the causes of death that are already known to be augmentable by alcohol accounted for only 5% of the deaths (1% liver disease, 2% cancer of the mouth, pharynx, larynx, or oesophagus, and 2% external causes of death) and were significantly elevated only among men consuming >2 units/day. Vascular disease and respiratory disease accounted for more than half of all the deaths and were both significantly less common among current than among non-drinkers; hence, overall mortality was also significantly lower (relative risk, RR 0.81, CI 0.76–0.87, P = 0.001). The non-drinkers, however, include the ex-drinkers, some of whom may have stopped recently because of illness, and during the last decade of the study (1991–2001) overall mortality was significantly higher in the few ex-drinkers who had been current drinkers in 1978 than in the never-drinkers or current drinkers. To avoid bias, these 239 ex-drinkers were considered together with the 6271 current drinkers and compared with the 750 [?misprint, do they mean 7500; that’s the only way to get to 12,000] men who had been non-drinkers in both questionnaires. Even so, ischaemic heart disease (RR 0.72, CI 0.58–0.88, P = 0.002), respiratory disease (RR 0.69, CI 0.52–0.92, P = 0.01), and all-cause (RR 0.88, CI 0.79–0.98, P = 0.02) mortality were significantly lower than in the non-drinkers.

Conclusions Although some of the apparently protective effect of alcohol against disease is artefactual, some of it is real.

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